I am trying to use LWJGL using the Get Started example (from https://www.lwjgl.org/guide {which unaltered works fine}), but altering it so it uses OpenGL ES 3.0 instead (for reasons irrelevant to this question).
I am using the latest LWJGL Release 3.1.1, selecting Minimal OpenGL ES as my preset (from https://www.lwjgl.org/download ) and using windows natives. (I am running Windows 10 64bit)
I'm stuck--I'm not sure how to fix it, and get it to run.
The error I get is:
Exception in thread "main" java.lang.IllegalStateException: There is no OpenGL ES context current in the current thread.
The complete error:
Exception in thread "main" java.lang.IllegalStateException: There is no OpenGL ES context current in the current thread.
at org.lwjgl.opengles.GLES.createCapabilities(GLES.java:222)
at com.test.desktop.HelloWorld.loop(HelloWorld.java:93)
at com.test.desktop.HelloWorld.run(HelloWorld.java:31)
at com.test.desktop.HelloWorld.main(HelloWorld.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
Complete source:
package com.test.desktop;
import org.lwjgl.*;
import org.lwjgl.glfw.*;
//import org.lwjgl.opengl.*;
import org.lwjgl.opengles.GLES;
import org.lwjgl.system.*;
import java.nio.*;
import static org.lwjgl.glfw.Callbacks.*;
import static org.lwjgl.glfw.GLFW.*;
//import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengles.GLES20.*;
import static org.lwjgl.opengles.GLES30.*;
import static org.lwjgl.system.MemoryStack.*;
import static org.lwjgl.system.MemoryUtil.*;
public class HelloWorld {
// The window handle
private long window;
static final int WIDTH = 1024;
static final int HEIGHT = 768;
public void run() {
System.out.println("Hello LWJGL " + Version.getVersion() + "!");
init();
loop();
// Free the window callbacks and destroy the window
glfwFreeCallbacks(window);
glfwDestroyWindow(window);
// Terminate GLFW and free the error callback
glfwTerminate();
glfwSetErrorCallback(null).free();
}
private void init() {
// Setup an error callback. The default implementation
// will print the error message in System.err.
GLFWErrorCallback.createPrint(System.err).set();
// Initialize GLFW. Most GLFW functions will not work before doing this.
if ( !glfwInit() )
throw new IllegalStateException("Unable to initialize GLFW");
// Configure GLFW
glfwDefaultWindowHints(); // optional, the current window hints are already the default
glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); // the window will stay hidden after creation
glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); // the window will be resizable
// Create the window
window = glfwCreateWindow(WIDTH, HEIGHT, "Hello World!", NULL, NULL);
if ( window == NULL )
throw new RuntimeException("Failed to create the GLFW window");
// Setup a key callback. It will be called every time a key is pressed, repeated or released.
glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
if ( key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE )
glfwSetWindowShouldClose(window, true); // We will detect this in the rendering loop
});
// Get the resolution of the primary monitor
GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());
// Center the window
glfwSetWindowPos(
window,
(vidmode.width() - WIDTH) / 2,
(vidmode.height() - HEIGHT) / 2
);
// Make the OpenGL context current
glfwMakeContextCurrent(window);
// Enable v-sync
glfwSwapInterval(1);
// Make the window visible
glfwShowWindow(window);
}
private void loop() {
// This line is critical for LWJGL's interoperation with GLFW's
// OpenGL context, or any context that is managed externally.
// LWJGL detects the context that is current in the current thread,
// creates the GLCapabilities instance and makes the OpenGL
// bindings available for use.
GLES.createCapabilities();
// GL.createCapabilities();
// Set the clear color
glClearColor(1.0f, 0.0f, 0.0f, 0.0f);
// Run the rendering loop until the user has attempted to close
// the window or has pressed the ESCAPE key.
while ( !glfwWindowShouldClose(window) ) {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // clear the framebuffer
glfwSwapBuffers(window); // swap the color buffers
// Poll for window events. The key callback above will only be
// invoked during this call.
glfwPollEvents();
}
}
public static void main(String[] args) {
new HelloWorld().run();
}
}
Whether it is worth noting... if I uncomment:
import org.lwjgl.opengl.*;
And, change:
GLES.createCapabilities();
And, use the following instead:
GL.createCapabilities();
I get this error:
Exception in thread "main" java.lang.IllegalStateException: No GLESCapabilities instance set for the current thread. Possible solutions:
Managed to find a solution (from http://bedroomcoders.co.uk/gles2-0-everywhere-thanks-to-lwjgl3/ ).
I uncomment:
import org.lwjgl.opengl.*;
Before the glfwCreateWindow function is called in the init() function, added:
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
And, added the following to end of the init() function:
// Bypasses the default create() method.
Configuration.OPENGLES_EXPLICIT_INIT.set(true);
GLES.create(GL.getFunctionProvider());
This works because it uses org.lwjgl.opengles.GL function addresses instead of org.lwjgl.opengles.GLES . On Windows they use OpenGL native function addresses regardless (with some exceptions).
"OpenGL 4.3 provides full compatibility with OpenGL ES 3.0" (from https://en.wikipedia.org ).
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